A GMAW or MIG welding torch allows a user or robot to direct an electrode metal wire and welding current toward a target work piece. The electrode metal wire is continuously fed from a spool and consumed as the welding process progresses. Components of a GMAW or MIG welding torch include consumables such as a contact tip, a nozzle, and a diffuser. The electrode metal wire feeds through a passageway in the contact tip. The welding current flows through the diffuser and the contact tip. The inert gas flows from passages in the diffuser, and the nozzle guides the gas towards the tip of the electrode metal wire.